Well, as it turns out, you actually need your cuticles to protect your nail beds from infection and those white marks on your fingernails may have nothing to do with your calcium consumption.

For a little Nail 101 and to get to the bottom of all the nail myths we’ve heard over the years, we reached out to Nu Skin’s nail health expert, Dr. Stern. Stern is one of the only board-certified dermatologists who has devoted her entire practice to all things nails, including the diagnosis, treatment, and surgery of the nail.

Below are the most common myths we’ve heard concerning the look, health and overall appearance of nails. Read on to hear Dr. Stern is set the record straight on these popular old wives’ tales once and for all.

“The cuticle is the nail’s natural protective seal that prevents the entry of organisms and moisture into the nail unit,” explains Dr. Stern. “Avoid cutting the cuticle. Instead, gently push the cuticle back with a washcloth after a warm shower or bath and follow with your favorite cuticle moisturizer. Chemical cuticle removers, which are very popular in salons, are the same thing as cutting. Look for products that are rich in phospholipids (like sunflower oil) and that contain antioxidants such as rosemary or apricot oil. Apply throughout the day if cuticles are especially dry.”

2. Myth: You can wear nail polish as long as you want.

If you only remove your nail polish once it starts to chip, you could risk infection or developing white marks.

“While nail polish adds a little style or pizazz to nails, one common mistake is simply wearing nail polish, which can do damage if left on too long or applied without a clear base coat,” says Dr. Stern. “This is especially true for the toenails, where it’s easy to leave polish on for over a month.”

Wrong. If you notice white marks on your fingernails, it’s not an indicator of your calcium intake or fungus. Those small white spots are related to your nails’ keratin structure, and are usually a sign that your nails are brittle or weak.

“These keratin granulations are areas where the superficial layers of nail cells (onychocytes) have been inadvertently removed along with the polish,” Dr. Stern suggests. “They [white marks] tend to grow out as the nail grows and can fade with time. To prevent brittle nails, always wear gloves for household chores, especially when washing dishes. Also, avoid excessive use of hand sanitizers that contain alcohol, because alcohol is extremely drying to nails and skin. Instead, consider using a moisturizing cleanser or body wash in a travel dispenser.”

4. Myth: Eating Jell-O can strengthen dry, brittle nails.

Not exactly. Though Jell-O does contain similar proteins found in human fingernails, going on a Jell-O diet or dipping your nails in the jiggly gelatin isn’t a form of treatment for weak nails.

“During the Great Depression, Jell-O was an inexpensive dietary protein source and was recommended for healthy nails,” says Dr. Stern. “Nails are made of protein, and nail health depends on an adequate, protein-rich diet. Today, in the Western world, since it’s extremely rare to see protein deficiency, it’s not necessary to consume Jell-O as a dietary supplement.”

5. Myth: Nails have to breathe.

False! If your digits are damaged, it has nothing to do with how little oxygen or ambient air your nails are getting.

“Nails do not need to ‘breathe,’ explains Dr. Stern. “Nails receive their nutrients, oxygen and blood supply from the blood stream and not from the air. If you are a weekly manicure gal, and your nails are tolerating it, then polish away. If you are noticing that your nails are peeling, dry, weak or thin, then your nails simply need a break.”

6. Myth: Ice water helps your nails dry faster.

Sorry, ladies. Giving your nails an ice bath won’t make your nails dry faster, at least not the underlying layers. Which explains why you won’t see your nail tech attempting to submerge your fingers in ice water at the salon.

Instead, Dr. Stern recommends using a fan or quick dry drops if you’re in a hurry. That way, you can ensure the entire nail is dry, as opposed to just the top layer.

7. Myth: To revive an old bottle of nail polish, add nail polish remover or store the bottle in the fridge.

Surprisingly, these myths are sort of true—emphasis on the sort of.

“Adding polish remover or thinner to polish will stretch out your favorite polish,” reveals Dr. Stern. “But it will also dilute the formula and compromise its integrity, giving you a streaky manicure.”

And, yes, you’ll be glad to know you can keep nail polish in the fridge for years

“Polish likes cool, dry places,” confirms Dr. Stern. “While the fridge is great, it [nail polish] is also fine to store in room temperature areas that are not super humid, sunny or heated.”